The present invention relates to an improved storage rack for drilling tubulars. Throughout this application the term "drilling tubulars" will be used in its broad sense to encompase drill pipe, drill collars and casing, as well as other types of tubular structures used in connection with boreholes such as production tubing, sucker rods, and the like.
In well drilling and well service operations a large quantity of drilling tubulars must be stored. For example, in well drilling operations drill pipe (which is typically stored horizontally at ground level) must be moved to a vertical position and then coupled to a drill string. Similarly, when a drill string is being removed from a bore hole, consecutive lengths of drill pipe must be removed from the drill string and brought to ground level in a horizontal orientation.
Various types of transfer arms have been devised to speed the handling of downhole tubulars and the transfer of such tubulars between the horizontal, ground level position and the elevated, vertical position aligned with the bore hole. Such transfer arms can significantly reduce the manpower needed to operate a drilling rig.
However, a need exists for an improved rack for drilling tubulars which can act to support the drilling tubulars at ground level in a horizontal orientation, and to feed the stored tubulars from the rack to a transfer arm. Such an improved rack offers the prospect of further significant reductions in the manpower required to operate a drilling rig.